The coach addressed the media on Wednesday afternoon and showed his support for the Barca star, who has been criticised in the past for not delivering in national team colours
The match will be Argentina’s first under Sabella after the dismissal of his predeccesor, Sergio Batista, and the coach addressed the issue of the form of Messi.
The former Estudiantes boss opined that the 24-year-old's displays for Barcelona and Argentina cannot be set against each other, stating to the media: “Messi is the best player in the world both at club and international level. We can’t compare Barcelona and Argentina because the two teams are on different paths.
"Barca have players who have been playing for years and at Argentina or any other national team, we don’t get to see all the players week in week out so there is no point having a comparison."
He confirmed that Messi will be captain during the World Cup qualifiers as well as in Friday's friendly, and added that the match will allow him to gauge the level of his team before the World Cup qualifying campaign for Brazil 2014 commences.
“Messi will be captain during the qualifiers and hopefully if we qualify for Brazil 2014 he will lead the side there also." said Sabella.
“I believe it is the start of our journey to the World Cup as it is my first game in charge so we need to give a good performance and build confidence ahead of the World Cup qualifiers."
Sabella also explained Carlos Tevez’s expulsion from the squad that has travelled to Kolkata, and claimed that the Manchester City attacker is still very much in his plans.
“When I named the squad for this match, Tevez wasn’t in the right shape but he has now started playing for Man City and we are keeping a close eye on his progress. Good players like him are always in my plans."